1. Field of the Invention
The present invention is one that pertains to technology providing a display device.
2. Description of the Related Art
In recent years, along with the spread of Personal Computers as well as IT (Information Technology) infrastructure development, projection type image display devices, starting with projectors, have spread with high speed in various settings such as at conference presentations and for lectures at education sites.
Moreover, accompanying the spread, the trend toward higher luminance is advancing together with a reduction in price. As a result hereof, since it has not been possible in the past to obtain sufficient brightness for display images of projection type image display devices, it has been necessary to project on a dedicated screen to make the projection. Under present conditions, since it is possible to procure projection type image display devices comparatively inexpensively and with high luminance, it is possible to ensure sufficient brightness even without making a projection on a dedicated screen, so cases in which projections are made on recording facilities such as whiteboards and blackboards have also gradually become more numerous.
On the other hand, a recording facility onto which a projection is made is an important tool with which tables and characters are recorded to carry out communication of intent, but since there are different objectives at the time of recording, there is a situation in which it cannot be said that guide displays such as to make tables easy to write or record characters by alignment in either the horizontal or vertical direction are sufficient. As far as whiteboards are concerned, there are box-shaped guide displays or printed guide letters which are put to practical use as recording aids, but since the objectives of use at the time of recording are diverse, the situation is one which cannot be said to be sufficient.
Accordingly, the situation is one in which settings of use where a projection type image display device projects onto the aforementioned facility to display an image are becoming numerous and it is possible to display arbitrary auxiliary lines from the projection type image display device to carry out assistance in recording. Regarding the concerned functionality, it is one that is disclosed in JP-A-2005-250391.